Electronic device in which different types of bateries can be selectively used as a power source

ABSTRACT

An electronic device includes a battery chamber; first through fifth contacts,. positioned in the battery, chamber; two detection switches which are turned ON only when two battery packs are accommodated in the battery chamber in the correct direction; a voltage detector capable of detecting first through sixth voltages between the first/second contacts, second/third contacts, third/fourth contacts, fourth/fifth contacts, first/third contacts, and third/fifth contacts, respectively; and a controller which allows either four cylindrical cells or the two battery packs to be used as the power source only if the two detection switches are ON when the fifth and sixth voltages are substantially the same, or if the two detection switches are OFF when the first, second, third and fourth voltages is greater than zero volts and that the first, second, third and fourth voltages are substantially the same.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an electronic device such as anelectronic camera which is powered by battery, more specifically, to anelectronic device in which different types of batteries can beselectively used as a power source.

[0003] 2. Description of the Related Art

[0004] A cylindrical primary CR-V3 lithium battery (manganesedioxide/lithium battery) which is interchangeable with two AA-size cells(two primary or secondary AA-size cells), has been available on themarket in recent years. Furthermore, various cameras for which one ormore CR-V3 batteries are available as a power source have been developedin recent years. Primary lithium. batteries are high in weight energydensity and volume energy density, and are accordingly suitable as apower source for high-power consumption electronic devices such asdigital cameras. FIGS. 11 and 12 each show an outward appearance of aCR-V3 battery.

[0005] Since the CR-V3 battery is accommodated in a battery chamber, inwhich two AA-size cells can be accommodated, there is a possibility ofone CR-V3 battery and two or more AA-size cells being intentionally orunintentionally accommodated together in a battery chamber of a camerain which four or a larger even number of AA-size cells can beaccommodated to serve as a power source of the camera. For example, in acamera using four AA-size cells, there is a possibility of two AA-sizecells and one CR-V3 battery being accommodated in the battery chamberand subsequently being used in such a state. Additionally, there is apossibility of four AA-size cells which includes both primary andsecondary cells being accommodated in the battery chamber andsubsequently being used in such a state.

[0006] Accordingly, if either a combination of two or more AA-sizeprimary cells and at least one CR-V3 battery, or a combination of two ormore AA-size primary cells and two or more AA-size secondary cells areaccommodated together in a battery chamber of a camera which canaccommodate at least four or a larger even number of AA-size cells, theAA-size primary cells may be forcibly charged accidentally due to adifference in voltage between the AA-size primary cells and the CR-V3battery or the AA-size secondary cells, even though the AA-size primarycells are non-rechargeable batteries. If a voltage for battery chargingis applied to the AA-size primary cells, the AA-size primary cells mayresult in battery fluid leak, heat generation, damage and/or explosion,which is dangerous. Such improper use of batteries cannot besufficiently prevented from occurring even if an instruction manualcalls attention to such a danger.

SUMMARY OF THE INVENTION

[0007] The present invention has been devised in view of the problemsnoted above. The present invention provides an electronic device (e.g.,a camera) including a battery chamber, in which at least two batterypacks of the same type each having a shape interchangeable with twocylindrical cells of the same type can be accommodated so that eitherthe two battery packs or two sets of the two cylindrical cells can beselectively accommodated in the battery chamber, wherein a combinationof different types of batteries can be prevented from being accommodatedand used as a power source of the electronic device.

[0008] According to the present invention, an electronic device forwhich at least two different types of batteries can be selectively usedas a power source is provided, the electronic device-including a batterychamber, in which at least two battery packs of the same type eachhaving a shape interchangeable with two cylindrical cells of the sametype can be accommodated so that either the two battery packs or twosets of the two cylindrical cells can be selectively accommodated in thebattery chamber, wherein each of the two battery packs includes apositive terminal and a negative terminal which are formed on only oneend of the each battery pack, and wherein each of the two cylindricalcells includes a positive terminal and a negative terminal which arerespectively formed on opposite ends of the each cylindrical cell; firstthrough fifth contacts, positioned alternately between opposite ends ofthe battery chamber, in a longitudinal direction of the cylindricalcells or battery packs which are accommodated in the battery chamber,wherein the first through fifth contacts connect the two sets of the twocylindrical cells in series in a case where each of the two sets of thetwo cylindrical cells is accommodated in the battery chamber in thecorrect direction, and wherein in the case where the two battery packsare accommodated in the battery chamber, the third contact is inelectrical contact with the negative terminal of one of the two batterypacks and the positive terminal of the other of the two battery backswhile the first contact and the fifth contact are in electrical contactwith the positive terminal of the one of the two battery packs and thenegative terminal of the other of the two battery backs, respectively;two detection switches which are turned ON only when the two batterypacks are accommodated in the battery chamber in the correct direction,respectively; a voltage detector capable of detecting each of a firstvoltage between the first contact and the second contact, a secondvoltage between the second contact and the third contact, a thirdvoltage between the third contact and the fourth contact, a fourthvoltage between the fourth contact and the fifth contact, a fifthvoltage between the first contact and the third contact, and a sixthvoltage between the third contact and the fifth contact; and acontroller which allows either the two sets of the two cylindrical cellsor the two battery packs that are accommodated in the battery chamber tobe used as the power source only in one of the following two cases: afirst case where both the two detection switches are ON while it isdetermined via the voltage detector that the fifth voltage and the sixthvoltage are substantially the same as each other, and a second casewhere both the two detection switches are OFF while it is determined viathe voltage detector that each of the first voltage, the second voltage,the third voltage and the fourth voltage is greater than zero volts andthat the first voltage, the second voltage, the third voltage and thefourth voltage are substantially the same as each other.

[0009] The electronic device can include a warning device; and a backupbattery provided independently of the two sets of the two cylindricalcells and the two battery packs. In a case other than the first andsecond cases, the controller issues a warning that inappropriatebatteries are accommodated in the battery chamber via the warning devicewhile using the backup battery as a power source, and prohibits theinappropriate batteries from being used as a power source.

[0010] The warning device can include a display device. The controllerdrives the display device to indicate the warning in the case other thanthe first and second cases.

[0011] It is desirable for each cylindrical cell to include an AA-sizedcell, and for each battery pack to include a CR-V3 battery.

[0012] It is desirable for each of the two detection switches to includea movable switch portion which projects into the battery chamber, themovable switch portion being pressed by a side surface of associated theCR-V3 battery when the associated CR-V3 battery is inserted into thebattery chamber.

[0013] The electronic device can be a camera.

[0014] It is desirable for the battery chamber to be partitioned into afirst partition and a second partition, in each of which either the twocylindrical cells or one of the two battery packs can be accommodated.The electronic device can include a battery chamber lid for opening andclosing the battery chamber. The second contact and the fourth contactare fixed to an inner surface of the battery chamber lid in a manner toface the first partition and the second partition, respectively, in aclosed state of the battery chamber lid.

[0015] The battery chamber can be formed in a grip portion of thecamera.

[0016] Two of the CR-V3 batteries can be accommodated in the batterychamber with respective grooves portions of the two of the CR-V3batteries facing each other.

[0017] In another embodiment, an electronic device for which at leasttwo different types of batteries can be selectively used as a powersource is provided, the electronic device including a battery chamber,in which at least two battery packs of the same type each having a shapeinterchangeable with two cylindrical cells of the same type can beaccommodated so that either the two battery packs or two sets of the twocylindrical cells can be selectively accommodated in the batterychamber.

[0018] It is desirable for each cylindrical cell to include an AA-sizedcell, and for each battery pack to include a CR-V3 battery.

[0019] In another embodiment, an electronic device for which at leasttwo different types of batteries can be selectively used as a powersource is provided, the electronic device including a battery chamber,in which at least two battery packs of the same type each having a shapeinterchangeable with two cylindrical cells of the same type can beaccommodated so that either the two battery packs or two sets of the twocylindrical cells can be selectively accommodated in the batterychamber; a voltage detector capable of detecting a voltage for each ofthe two sets of the two cylindrical cells or the two battery packs whichare accommodated in the battery chamber; and a determining device whichdetermines that different types of batteries are accommodated in thebattery chamber in the case where all of the voltages detected by thevoltage detector are not substantially the same.

[0020] In a case where the determining device determines that thedifferent types of batteries are accommodated in the battery chamber, itis desirable for the different types of batteries to be prohibited frombeing used as a power source.

[0021] It is desirable for each cylindrical cell to be an AA-sized cell,and for each battery pack to be a CR-V3 battery.

[0022] The present disclosure relates to subject matter contained inJapanese Patent Application No.2003-055401 (filed on Mar. 3, 2003) whichis expressly incorporated herein by reference in its entirety.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be described below in detail withreference to the accompanying drawings in which:

[0024]FIG. 1 is an exploded perspective view of a battery case and abattery chamber lid which constitute a battery chamber of a camera bodyaccording the present invention;

[0025]FIG. 2 is a perspective view of the camera body including thebattery case and the battery chamber lid which are shown in FIG. 1;

[0026]FIG. 3 is a perspective view of the battery case and the batterychamber lid;

[0027]FIG. 4 is a perspective view of the battery case and the batterychamber lid, viewed from a different angle;

[0028]FIG. 5 is a perspective view of the battery case and the batterychamber lid, viewed from a different angle;

[0029]FIG. 6 is a cross sectional view of the battery case, viewed fromabove the battery case, showing a state where two CR-V3 batteries areaccommodated in the battery chamber;

[0030]FIG. 7. is a cross sectional view of the battery case, viewed fromabove the battery case, showing a state where four AA-size cells areaccommodated in the battery chamber;

[0031]FIG. 8 is a cross sectional view of the battery case, viewed fromthe left side of the battery case, showing a state where two CR-V3batteries are accommodated in the battery chamber;

[0032]FIG. 9 is a schematic block diagram of components of the camerabody shown in FIG. 2;

[0033]FIG. 10 is a flow chart showing a battery check process which isperformed by a controller in the camera body shown in FIG. 2;

[0034]FIG. 11 is a perspective view of the CR-V3 battery;

[0035]FIG. 12 is a perspective view of the CR-V3 battery shown in FIG.11, viewed from a different angle;

[0036]FIG. 13 is a schematic diagram of a top wall of the battery case,viewed from above of the battery case, showing the arrangement of afirst contact, a third contact and a fifth contact on the top wall ofthe battery case; and

[0037]FIG. 14 is a schematic diagram of the battery chamber lid, viewedfrom the inside of the battery chamber, showing the arrangement of asecond contact and a fourth contact on an inner surface of the batterychamber lid.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0038]FIG. 2 shows a camera body to which the present invention isapplied, and FIG. 9 shows components of the camera body shown in FIG. 2.The camera body 10 is that of an SLR type AF digital camera system. Thecamera body 10 is provided on a front surface thereof with a mount ring11 to which an interchangeable photographing lens 40 (see FIG. 9; notshown in FIG. 2) is detachably attached. The camera body 10 is providedin the vicinity of the mount ring 11 with a lens-lock-release button 12which is depressed when the photographing lens 40 is removed.

[0039] The camera body 10 is provided, on a left side portion thereof asviewed from front of the camera body 10, with a grip portion 13, and isprovided on top of the grip portion 13 with a release button (notshown). The camera body 10 is provided, on a bottom surface thereof atan approximate center of the bottom surface, with a tripod socket(female screw hole) 14, and is provided at the bottom of the gripportion 13 with a battery chamber lid (battery chamber cover) 15 foropening and closing a battery chamber BC of the camera body 10.

[0040] The camera body 10 is provided in the grip portion 13 with astationary battery case 20. FIGS. 1, 3, 4 and 5 show the battery case 20and the battery chamber lid 15 which constitute the battery chamber BC.The battery case 20 is a tubular case whose top end and bottom end areclosed and open, respectively, and is formed so that either four AA-sizecells (each designated by “AA” in the drawings) or two CR-V3 batteries(battery packs) (each designated by “CR-V3 ” in the drawings) can beaccommodated in the battery chamber BC in the battery case 20. Anapproximately upper half of the battery chamber BC is partitioned intotwo partitions: a first partition 21 and a second partition 22 by apartition wall 20 a (see FIGS. 1, 6 and 8). The partition wall 20 a ispositioned in the battery chamber BC is formed integral with the batterycase 20, and extends in a vertical direction of the camera body 10.Either two AA-size cells or one CR-V3 battery can be inserted into eachof the first partition 21 and the second partition 22.

[0041] As shown in FIGS. 6, 11 and 12, the CR-V3 battery has a shapewhich is interchangeable with two AA-size cells. The CR-V3 battery isprovided on one side thereof with a flat portion 101 which extends froma position slightly below the center thereof to the bottom end of theCR-V3 battery, as viewed in FIGS. 11 and 12, and a groove portion 102which extends from the top end of the flat portion 101 to the top end ofthe CR-V3 battery, as viewed in FIGS. 11 and 12. When the CR-V3 batteryis inserted into the first partition 21 or the second partition 22 inthe battery chamber BC, the CR-V3 battery is inserted from a specificend thereof (the top end as viewed in FIGS. 11 and 12) on which apositive terminal and a negative terminal are provided. Upon insertionof the CR-V3 battery into the first partition 21 or the second partition22, the flat portion 101 and the groove portion 102 faces the partitionwall 20 a. As shown in FIGS. 6 and 7, a central portion of the partitionwall 20 a bulges in forward/rearward directions (upward/downwarddirections as viewed in FIGS. 6 and 7) perpendicular to the direction ofinsertion of the CR-V3 battery. The shape of the partition wall 20 aprevents the CR-V3 battery from being inserted into the battery chamberBC back-to-front due to the groove portion 102 of the CR-V3 batterycorresponding to the shape of the partition wall 20 a (i.e., due to theside opposite to that of the groove portion 102 interfering with thepartition wall 20 a if inserted back-to-front), and further prevents theCR-V3 battery from being inserted into the battery chamber BC in thereverse direction (i.e., from the bottom end as viewed in FIGS. 11 and12) due to the flat portion 101 of the CR-V3 battery interfering withthe partition wall 20 a if inserted in the reverse direction. In otherwords, each of the first partition 21 or the second partition 22, whichare partitioned by the partition wall 20 a, is formed to have a shapecorresponding to the shape of an approximately upper half of the CR-V3battery (approximately upper half as viewed in FIGS. 11 and 12).

[0042] As shown in FIG. 1, the battery case 20 is provided at a bottomend surface thereof with a first lug engaging portion 20 b and a secondlug engaging portion 20 c, and the battery chamber lid 15 is provided onan inner side thereof with a first lug 15 b and a second lug 15 c whichare engaged in the first lug engaging portion 20 b and the second lugengaging portion 20 c, respectively, when the battery chamber lid 15 isclosed.

[0043] The rear end of the battery chamber lid 15 is pivoted at a bottomwall 16 of the camera body 10. More specifically, the battery chamberlid 15 is provided at the rear end thereof with a pair of pivots 15 awhich project in right/left directions of the camera body 10 so that thepair of pivots 15 a are rotatably supported by a pair of pivot supportportions (not shown), respectively, which are formed on an inner surfaceof the bottom wall 16 of the camera body 10. The pair of pivot supportportions that are formed on the bottom wall 16 are formed to allow thepair of pivots 15 a to move in forward/rearward directions by apredetermined amount of movement.

[0044] In a state where the battery chamber lid 15 is closed, i.e.,where the first lug 15 b and the second lug 15 c are respectivelyengaged in the first lug engaging portion 20 b and the second lugengaging portion 20 c, sliding the battery chamber lid 15 slightlyforward relative to the camera body 10 causes the first lug 15 b and thesecond lug 15 c to be disengaged from the first lug engaging portion 20b and the second lug engaging portion 20 c, respectively, therebyopening the battery chamber lid 15. To close the battery chamber lid 15,the first lug 15 b and the second lug 15 c only need to be engaged inthe first lug engaging portion 20 b and the second lug engaging portion20 c, respectively.

[0045] A first contact 24, a second contact 28, a pair of third contacts25 and 26, a fourth contact 29 and a fifth contact 27 are alternatelyfixed to a top wall 23 of the battery case 20 and an inner surface ofthe battery chamber lid 15. Namely, the first contact 24, the pair ofthird contacts 25 and 26 and the fifth contact 27 are fixed to the topwall 23 of the battery case 20, while the second contact 28 and thefourth contact 29 are fixed to an inner surface of the battery chamberlid 15. FIGS. 13 and 14 are schematic diagrams showing the arrangementof the first through fifth contacts that are positioned alternatelybetween opposite ends of the battery chamber BC in a longitudinaldirection of the batteries (either four AA-size cells or two CR-V3batteries) accommodated in the battery chamber BC. The first contact 24and the fifth contact 27, which are positioned on the top wall 23 of thebattery case 20, always serve as contacts from which a voltage is taken.The first contact 24 and the third contact 25 are positioned at theupper end of the first partition 21 in the battery chamber BC, while thethird contact 26 and the fifth contact 27 are positioned at the upperend of the second partition 22 in the battery chamber BC. The firstcontact 24 and the third contact 25 contact the positive terminal of oneAA-sized cell and the negative terminal of another AA-sized cell,respectively, when two AA-sized cells are inserted into the firstpartition 21, or contact the positive and negative terminals of theCR-V3 battery, respectively, when the CR-V3 battery is inserted into thefirst partition 21. The third contact 26 and the fifth contact 27contact the positive terminal of one AA-sized cell and the negativeterminal of another AA-sized cell, respectively, when two AA-sized cellsare inserted into the second partition 22, or contact the positive andnegative terminals of the CR-V3 battery, respectively, when the CR-V3battery is inserted into the second partition 22. A conductive wire W isconnected between the pair of third contacts 25 and 26 for conduction ofelectricity therebetween (see FIG. 4).

[0046] On the other hand, the second contact 28, which is fixed to thebattery chamber lid 15, is provided with a first contacting portion 28 aand a second contacting portion 28 b which face the first contact 24 andthe third contact 25, respectively, in a closed state of the batterychamber lid 15. Likewise, the fourth contact 29 is provided with a firstcontacting portion 29 a and a second contacting portion 29 b which facethe third contact 26 and the fifth contact 27, respectively, in a closedstate of the battery chamber lid 15.

[0047] When two AA-sized cells are inserted into the first partition 21,the first contacting portion 28 a of the second contact 28 contacts thenegative terminal of one AA-sized cell, while the second contactingportion 28 b of the second contact 28 contacts the positive terminal ofanother AA-sized cell. Likewise, when two AA-sized cells are insertedinto the second partition 22, the first contacting portion 29 a of thefourth contact 29 contacts the negative terminal of one AA-sized cell,while the second contacting portion 29 b of the fourth contact 29contacts the positive terminal of another AA-sized cell.

[0048] The second contacting portion 28 b of the second contact 28 isprovided with a power-interruption prevention spring 28 c whichresiliently contacts the positive terminal of an AA-sized cell.Likewise, the second contacting portion 29 b of the fourth contact 29 isprovided with a power-interruption prevention spring 29 c whichresiliently contacts with the positive terminal of an AA-sized cell.

[0049] The battery chamber lid 15 is provided on an inner surfacethereof on respective sides of the second contacting portion 28 b with apair of reverse-contact preventing projections 15 d for preventing thenegative terminal of an AA-sized cell from contacting with thepower-interruption prevention spring 28 c. The battery chamber lid 15 isprovided on an inner surface thereof on respective sides of the secondcontacting portion 29 b with another pair of reverse-contact preventingprojections 15 d for preventing the negative terminal of an AA-sizedcell from contacting with the power-interruption prevention spring 29 c.

[0050] When two CR-V3 batteries are inserted into the battery chamberBC, neither the second contact 28 nor the fourth contact 29 contacts anyterminals of the CR-V3 batteries since the CR-V3 battery does not haveany terminal at the bottom thereof.

[0051] As shown in FIG. 8, a first detection switch 31 for detecting thepresence or absence of the CR-V3 battery in the first partition 21 isfixed to an outside wall of the battery case 20 adjacent to the firstpartition 21, and a second detection switch 32 for detecting thepresence or absence of the CR-V3 battery in the second partition 22 isfixed to an outside wall of the battery case 20 adjacent to the secondpartition 22. The first detection switch 31 is provided with a movableswitch pin (movable switch portion) 31 a which projects into the firstpartition 21 through a through-hole 20 d formed on an associated sidewall of the battery case 20. The first detection switch 31 is OFF whenthe CR-V3 battery is not inserted into the first partition 21, i.e.,when the movable switch pin 31 a remains projecting into the firstpartition 21. In a state where the CR-V3 battery is inserted into thefirst partition 21, a side surface of the CR-V3 battery on which neitherthe flat portion 101 nor the groove portion 102 is formed presses themovable switch pin 31 a toward the outside of the first partition 21 tothereby turn ON the first detection switch 31.

[0052] Likewise, the second detection switch 32 is provided with amovable switch pin (movable switch portion) 32 a which projects into thesecond partition 22 through a through-hole 20 e formed on an associatedside wall of the battery case 20. The second detection switch 32 is OFFwhen the CR-V3 battery is not inserted into the second partition 22,i.e., when the movable switch pin 32 a remains projecting into thesecond partition 22. In a state where the CR-V3 battery is inserted intothe second partition 22, a side surface of the CR-V3 battery on whichneither the flat portion 101 nor the groove portion 102 are formedpresses the movable switch pin 32 a toward the outside of the secondpartition 22 to thereby turn ON the second detection switch 32. Thefirst detection switch 31 is not turned ON even if two AA-sized cellsare inserted into the first partition 21. Likewise, the second detectionswitch 32 is not turned ON even if two AA-sized cells are inserted intothe second partition 21.

[0053] As shown in FIG. 9, the camera body 10 is provided with aviewfinder optical system including a focusing screen 51, a pentagonalprism (pentaprism) 52 and an eyepiece 53. The camera body 10 is providedtherein below the focusing screen 51 with a quick-return mirror (firstmirror) 42. In a non-photographing state where the user can view anobject through the eyepiece 53, object light rays which enter the camerabody 10 through the photographing lens 40 mounted to the mount ring 11are reflected upwards by the quick-return mirror 42 to be formed as animage on the focusing screen 51. Subsequently, this image is laterallyreversed by the pentagonal prism 52 to be viewed as an erect imagethrough the eyepiece. The camera body 10 is provided between thepentagonal prism 52 and the eyepiece 53 with a photometer element 54which receives a part of the light rays emerging from an exit surface ofthe pentagonal prism 52. The camera body 10 is provided behind thequick-return mirror 42 with a focal plane shutter 45, an opticallow-pass filter 47 and a CCD image sensor (image pick-up device) 48. Thequick-return mirror 42 and the focal plane shutter 45 are driven by aconventional mirror/shutter drive mechanism 60.

[0054] In addition, in a non-photographing state where the user can viewan object through the eyepiece 53, a part of the object light rays whichhave entered the camera body 10 through the photographing lens 40 passesthrough a half mirror portion formed at an approximate center of thequick-return mirror 42 to be incident on a sub-mirror (second mirror) 43which is pivoted on a rear surface of the quick-return mirror 43. Thelight rays which are incident on the sub-mirror 43 are reflecteddownwards thereby to be incident on an AF sensor unit 44, e.g., aphase-difference detection AF sensor unit. Signals output from the AFsensor unit 44 are input to a CPU (controller/voltagedetector/determining device) 46 which comprehensively controls theoverall operation of the camera body 10. An AF drive mechanism 147 fordriving a focusing lens group (not shown) included in the photographinglens 40, a diaphragm drive mechanism 148 for driving a diaphragmmechanism 41 provided in the photographing lens 40, and an exposurecontrol circuit 49 to which the photometer element 54 is connected areconnected to the CPU 46.

[0055] In addition, a photometer/release switch 61 and an externaldisplay (warning device/display device) 62 (e.g., an LCD panel) areconnected to the CPU 46. The photometer/release switch 61 is operated bya release button (not shown) provided on a top-front surface of the gripportion 13. The external display 62 visually indicates variousinformation.

[0056] Upon the release button (not shown) being half depressed, aconventional photometric operation and a conventional distance measuringoperation commence via the photometer/release switch 61. Upon therelease button being fully depressed, a conventional shutter releaseoperation commences via the photometer/release switch 61.

[0057] The CCD image sensor 48 is connected to the CPU 46 via a CCDdriver 63 and a clock generator 64. Image data output from the CCD imagesensor 48 are stored in a memory 69 (e.g., a removable memory such as aflash memory) via an amplifier 65, an A/D converter 66, a signalprocessing circuit 67 and a data compression/non-compression circuit 68.

[0058] As shown in FIG. 9, the batteries (either four AA-sized cells ortwo CR-V3 batteries) accommodated in the battery chamber BC areconnected to the CPU 46 via a DC/DC converter 71, while the firstdetection switch 31 and the second detection switch 32 are connected tothe CPU 46.

[0059] The camera body 10 is provided therein with a backup battery 72(see FIG. 9) independently of the batteries accommodated in the batterychamber BC. The backup battery 72 is connected to the CPU 46 via theDC/DC converter 71. The backup battery 72 can be a button type lithiumbattery or any other type of battery.

[0060] Each of the first through fifth contacts 24 through 29 that arefixed to the battery case 20 or the battery chamber lid 15 (i.e., thefirst through sixth contacts) is connected to the CPU 46 so that the CPU46 obtains information on respective voltages between terminals.

[0061]FIG. 10 shows a flow chart showing a battery check process. In theprocess shown in FIG. 10, it is determined whether the batteriesaccommodated in the battery chamber BC are appropriate or not oncondition that batteries (AA-sized cells or CR-V3 batteries) are fullyaccommodated in the battery chamber CD, and thereafter, a predeterminedwarning indicator is indicated on the external display 62 while a mainpower switch (not shown) which is provided on top of the camera body 10is prohibited from being turned ON (i.e., the batteries accommodated inthe battery chamber BC are prohibited from being used as a main powersource of the camera body 10) if it is determined that the batteriesaccommodated in the battery chamber BC are inappropriate. This batterycheck process shown in FIG. 10 is performed by the CPU 46 with powersupplied thereto by the backup battery 72. The battery check processwill be hereinafter discussed in detail.

[0062] Immediately after batteries are loaded into the battery chamberBC (step S11), it is determined whether the first detection switch 31 isON (step S13). Control proceeds to step S15 if the first detectionswitch 31 is ON (if YES at step S13), or proceeds to step S25 if OFF (ifNO at step S13). It is determined at step S15 whether the seconddetection switch 32 is ON. Control proceeds to step S17 if the seconddetection switch 32 is ON (if YES at step S15), or proceeds to step S21if OFF (if NO at step S15). Accordingly, control proceeds to step S17 ifboth the first detection switch 31 and the second detection switch 32are ON (i.e., if two of the CR-V3 batteries are inserted into the firstpartition 21 and the second partition 22, respectively).

[0063] Note that in FIGS. 9, 13 and 14, the first contact 24 is alsodesignated as {circle over (1)}, the second contact 28 is alsodesignated as {circle over (2)}, the pair of third contacts 25 and 26are also designated as {circle over (3)}, the fourth contact 29 is alsodesignated as {circle over (4)}, and the fifth contact 27 is alsodesignated as {circle over (5)}, and these numerals are exclusively usedto denote the first through fifth contacts {circle over (1)} through{circle over (5)} in FIG. 10 for simplicity. At step S17 it isdetermined whether the voltage between the first contact ({circle over(1)}) 24 and the third contact ({circle over (3)}) 25 and the voltagebetween the third contact ({circle over (3)}) 26 and the fifth contact({circle over (5)}) 27 are substantially the same as each other. If thevoltages are substantially the same as each other (if YES at step S17),it is determined that the serviceable CR-V3 battery is inserted intoeach of the first partition 21 and the second partition 22 in thecorrect direction; based on this determination, the main power switch onthe camera body 10 is permitted to be turned ON (step S19).Subsequently, control ends the battery check process. If the voltagebetween the first contact ({circle over (1)}) 24 and the third contact({circle over (3)}) 25 and the voltage between the third contact({circle over (3)}) 26 and the fifth contact ({circle over (5)}) 27 arenot substantially the same as each other (if NO at step S17), controlproceeds to step S23.

[0064] If it is determined at step S17 that the voltage between thefirst contact ({circle over (1)}) 24 and the third contact ({circle over(3)}) 25 and the voltage between the third contact ({circle over (3)})26 and the fifth contact ({circle over (5)}) 27 are not substantiallythe same as each other (if NO at step S17), a predetermined warningindicator (first warning indication) is indicated on the externaldisplay 62 (step S23). Subsequently, the main power switch on the camerabody 10 is prohibited from being turned ON (step S39), and control endsthe battery check process.

[0065] The first warning indication can be textual information, forexample, “The camera possibly has a mixture of old and new batteriesand/or damaged batteries inserted therein. Replace with new batteries.”,is indicated on the external display 62 at step S23. Instead of suchtextual information, a sign or a mark which indicates a similar meaningcan be indicated on the external display 62 at step S23.

[0066] If it is determined at step S15 that the second detection switch32 is not ON (if NO at step S15), a predetermined warning indicator(second warning indication), which is different from the aforementionedwarning indicator (first warning indication) of step S23, is indicatedon the external display 62 (step S21). Subsequently, the main powerswitch on the camera body 10 is prohibited from being turned ON (stepS39), and control ends the battery check process.

[0067] The second warning indication can be textual information, forexample, “The camera possibly has different types of batteries insertedtherein. Replace batteries only with the same type of batteries.”, isindicated on the external display 62 at step S21. Instead of suchtextual information, a sign or a mark which indicates a similar meaningcan be indicated on the external display 62 at step S21.

[0068] If it is determined at step S13 that the first detection switch31 is not ON (if NO at step S13), it is determined whether the voltagebetween the first contact ({circle over (1)}) 24 and the second contact({circle over (2)}) 28 is greater than zero volts (step S25). If thevoltage is equal to or less than zero volts (if NO at step S25), apredetermined warning indicator (third warning indication) which isdifferent from each of the aforementioned two warning signs or marks(first and second warning indications) at steps S21 and S23 areindicated on the external display 62 (step S41). Subsequently, the mainpower switch on the camera body 10 is prohibited from being turned ON(step S39), and control ends the battery check process.

[0069] The third warning indication can be textual information, forexample, “Batteries possibly exhausted, or batteries possibly insertedin wrong direction. Check if each battery is inserted in the correctdirection.”, is indicated on the external display 62 at step S41.Instead of such textual information, a sign or a mark which indicates asimilar meaning can be indicated on the external display 62 at step S41.

[0070] If it is determined at step S25 that the voltage between thefirst contact ({circle over (1)}) 24 and the second contact ({circleover (2)}) 28 is greater than zero volts (if YES at step S25), it isdetermined whether the voltage between the second contact ({circle over(2)}) 28 and the third contact ({circle over (3)}) 25 is greater thanzero volts (step S27). If the voltage is equal to or less than zerovolts (if NO at step S27), control proceeds to step S41 so that theaforementioned third warning indication is indicated on the externaldisplay 62. Subsequently, the main power switch on the camera body 10 isprohibited from being turned ON (step S39), and control ends the batterycheck process.

[0071] If it is determined at step S27 that the voltage between thesecond contact ({circle over (2)}) 28 and the third contact ({circleover (3)}) 25 is greater than zero volts (if YES at step S27), it isdetermined whether the second detection switch 32 is ON (step S29). Ifthe second detection switch 32 is ON (if YES) at step S29, controlproceeds to step S21 so that the aforementioned second warningindication is indicated on the external display 62. Subsequently, themain power switch on the camera body 10 is prohibited from being turnedON (step S39), and control ends the battery check process. If the seconddetection switch 32 is OFF (if NO at step S29), control proceeds to stepS31.

[0072] At step S31, it is determined whether the voltage between thethird contact ({circle over (3)}) 26 and the fourth contact ({circleover (4)})29 is greater than zero volts. If the voltage is equal to orless than zero volts (if NO at step S31), control proceeds to step S41so that the aforementioned third warning indication is indicated on theexternal display 62. Subsequently, the main power switch on the camerabody 10 is prohibited from being turned ON (step S39), and control endsthe battery check process.

[0073] If it is determined at step S31 that the voltage between thethird contact ({circle over (3)}) 26 and the fourth contact ({circleover (4)}) 29 is greater than zero volts (if YES at step S31), it isdetermined whether the voltage between the fourth contact ({circle over(4)}) 29 and the fifth contact ({circle over (5)}) 27 is greater thanzero volts (step S33). If the voltage is equal to or less than zerovolts (if NO at step S33), control proceeds to step S41 so that theaforementioned third warning indication is indicated on the externaldisplay 62. Subsequently, the main power switch on the camera body 10 isprohibited from being turned ON (step S39), and control ends the batterycheck process.

[0074] If it is determined at step S33 that the voltage between thefourth contact ({circle over (4)}) 29 and the fifth contact ({circleover (5)}) 27 is greater than zero volts (if YES step S33), thefollowing four voltages: the voltage between the first contact ({circleover (1)}) 24 and the second contact ({circle over (2)}) 28, the voltagebetween the second contact ({circle over (2)}) 28 and the third contact({circle over (3)}) 25, the voltage between the third contact ({circleover (3)}) 26 and the fourth contact ({circle over (4)}) 29 and thevoltage between the fourth contact ({circle over (4)}) 29 and the fifthcontact ({circle over (5)}) 27 are substantially the same as each other(step S35). If these voltages are substantially the same as each other(if YES at step S35), it is determined that two serviceable AA-sizedcells of the same-grade (primary or secondary) are inserted into each ofthe first partition 21 and the second partition 22 in the correctdirection; based on this determination, the main power switch on thecamera body 10 is allowed to be turned ON (step S19). Subsequently,control ends the battery check process. If these voltages are notsubstantially the same as each other (if NO at step S35), the fourthwarning indication is indicated on the external display 62 (step S37).Subsequently, the main power switch on the camera body 10 is prohibitedfrom being turned ON (step S39), and control ends the battery checkprocess.

[0075] The fourth warning indication can be textual information, forexample, “The camera possibly has a mixture of old and new batteries,damaged batteries, and/or different grades of batteries (primary andsecondary) inserted therein. Replace with new batteries.”, is indicatedon the external display 62 at step S37. Instead of such textualinformation, a sign or a mark which indicates a similar meaning can beindicated on the external display 62 at step S37.

[0076] The present invention can be applied to not only a digital camerasuch as the above described embodiment of the digital camera but alsoany other type of camera. In other words, the present invention can beapplied to a conventional camera using silver-salt film, and can also beapplied to any electronic device other than an electronic camera.Namely, the present invention can be applied to any electronic devicesusing either at least two CR-V3 batteries or four or a larger evennumber of AA-size cells as a power source.

[0077] In addition, the present invention is not limited solely to theparticular case where either at least two CR-V3 batteries or four or alarger even number of AA-size cells are used as a power source of anelectronic device. Namely, the present invention can be applied to anyelectronic device having a battery chamber in which at least two batterypacks of the same type each having a shape interchangeable with twocylindrical cells of the same type can be accommodated so that eitherthe two battery packs or two sets of the two cylindrical cells can beselectively accommodated in the battery chamber, wherein each of the twobattery packs includes a positive terminal and a negative terminal whichare formed on only one end of the each battery pack, and wherein each ofthe two cylindrical cells includes a positive terminal and a negativeterminal which are respectively formed on opposite ends of the eachcylindrical cell, can be accommodated.

[0078] As can be understood from the foregoing, according to the presentinvention, in an electronic device such as an electronic cameraincluding a battery chamber, in which at least two battery packs of thesame type each having a shape interchangeable with two cylindrical cellsof the same type can be accommodated so that either the two batterypacks or two sets of the two cylindrical cells can be selectivelyaccommodated in the battery chamber, a combination of different types ofbatteries can be prevented from being accommodated and used as a powersource of the electronic device.

[0079] Obvious changes may be made in the specific embodiment of thepresent invention described herein, such modifications being within thespirit and scope of the invention claimed. It is indicated that allmatter contained herein is illustrative and does not limit the scope ofthe present invention.

What is claimed is:
 1. An electronic device for which at least twodifferent types of batteries can be selectively used as a power source,said electronic device comprising: a battery chamber, in which at leasttwo battery packs of the same type each having a shape interchangeablewith two cylindrical cells of the same type can be accommodated so thateither said two battery packs or two sets of said two cylindrical cellscan be selectively accommodated in said battery chamber, wherein each ofsaid two battery packs includes a positive terminal and a negativeterminal which are formed on only one end of said each battery pack, andwherein each of said two cylindrical cells includes a positive terminaland a negative terminal which are respectively formed on opposite endsof said each cylindrical cell; first through fifth contacts, positionedalternately between opposite ends of said battery chamber, in alongitudinal direction of said cylindrical cells or battery packs whichare accommodated in said battery chamber, wherein said first throughfifth contacts connect said two sets of said two cylindrical cells inseries in a case where each of said two sets of said two cylindricalcells is accommodated in said battery chamber in the correct direction,and wherein in the case where said two battery packs are accommodated insaid battery chamber, said third contact is in electrical contact withsaid negative terminal of one of said two battery packs and saidpositive terminal of the other of said two battery backs while saidfirst contact and said fifth contact are in electrical contact with saidpositive terminal of said one of said two battery packs and saidnegative terminal of said other of said two battery backs, respectively;two detection switches which are turned ON only when said two batterypacks are accommodated in said battery chamber in the correct direction,respectively; a voltage detector capable of detecting each of a firstvoltage between said first contact and said second contact, a secondvoltage between said second contact and said third contact, a thirdvoltage between said third contact and said fourth contact, a fourthvoltage between said fourth contact and said fifth contact, a fifthvoltage between said first contact and said third contact, and a sixthvoltage between said third contact and said fifth contact; and acontroller which allows either said two sets of said two cylindricalcells or said two battery packs that are accommodated in said batterychamber to be used as said power source only in one of the following twocases: a first case where both said two detection switches are ON whileit is determined via said voltage detector that said fifth voltage andsaid sixth voltage are substantially the same as each other and a secondcase where both said two detection switches are OFF while it isdetermined via said voltage detector that each of said first voltage,said second voltage, said third voltage and said fourth voltage isgreater than zero volts and that said first voltage, said secondvoltage, said third voltage and said fourth voltage are substantiallythe same as each other.
 2. The electronic device according to claim 1,further comprising: a warning device; and a backup battery providedindependently of said two sets of said two cylindrical cells and saidtwo battery packs, wherein, in a case other than said first and secondcases, said controller issues a warning that inappropriate batteries areaccommodated in said battery chamber via said warning device while usingsaid backup battery as a power source, and prohibits said inappropriatebatteries from being used as a power source.
 3. The electronic deviceaccording to claim 2, wherein said warning device comprises a displaydevice, and wherein said controller drives said display device toindicate said warning in said case other than said first and secondcases.
 4. The electronic device according to claim 1, wherein said eachcylindrical cell comprises an AA-sized cell, and wherein said eachbattery pack comprises a CR-V3 battery.
 5. The electronic deviceaccording to claim 4, wherein each of said two detection switchescomprises a movable switch portion which projects into said batterychamber, said movable switch portion being pressed by a side surface ofassociated said CR-V3 battery when said associated CR-V3 battery isinserted into said battery chamber.
 6. The electronic device accordingto claim 1, wherein said electronic device comprises a camera.
 7. Theelectronic device according to claim 1, wherein said battery chamber ispartitioned into a first partition and a second partition, in each ofwhich either said two cylindrical cells or one of said two battery packscan be accommodated, wherein said electronic device comprises a batterychamber lid for opening and closing said battery chamber, and whereinsaid second contact and said fourth contact are fixed to an innersurface of said battery chamber lid in a manner to face said firstpartition and said second partition, respectively, in a closed state ofsaid battery chamber lid.
 8. The electronic device according to claim 6,wherein said battery chamber is formed in a grip portion of said camera.9. The electronic device according to claim 5, wherein two of said CR-V3batteries are accommodated in said battery chamber with respectivegrooves portions of said two of said CR-V3 batteries facing each other.10. An electronic device for which at least two different types ofbatteries can be selectively used as a power source, said electronicdevice comprising: a battery chamber, in which at least two batterypacks of the same type each having a shape interchangeable with twocylindrical cells of the same type can be accommodated so that eithersaid two battery packs or two sets of said two cylindrical cells can beselectively accommodated in said battery chamber; and a detector fordetecting whether said two sets of said two cylindrical cells or saidtwo battery packs are accommodated in said battery chamber.
 11. Theelectronic device according to claim 10, wherein said each cylindricalcell comprises an AA-sized cell, and wherein said each battery packcomprises a CR-V3 battery.
 12. An electronic device for which at leasttwo different types of batteries can be selectively used as a powersource, said electronic device comprising: a battery chamber, in whichat least two battery packs of the same type each having a shapeinterchangeable with two cylindrical cells of the same type can beaccommodated so that either said two battery packs or two sets of saidtwo cylindrical cells can be selectively accommodated in said batterychamber; a voltage detector capable of detecting a voltage for each ofsaid two sets of said two cylindrical cells or said two battery packswhich are accommodated in said battery chamber; and a determining devicewhich determines that different types of batteries are accommodated insaid battery chamber in the case where all of said voltages detected bysaid voltage detector are not substantially the same.
 13. The electronicdevice according to claim 12, wherein, in a case where said determiningdevice determines that said different types of batteries areaccommodated in said battery chamber, said different types of batteriesare prohibited from being used as a power source.
 14. The electronicdevice according to claim 12, wherein said each cylindrical cellcomprises an AA-sized cell, and wherein said each battery pack comprisesa CR-V3 battery.